Process of treating grains



June 13, 1933. w. LARSEN PROCESS OF TREATING GRAINS Filed June 18, 1930 4 Sheets-Sheet 1 A1- TORNE r June 13, 1933. w. LARSEN 1,914,341

PROCESS OF TREATING GRAINS Filed June 18, 1930 4 Sheets-Sheet 2 VE/vrae ATTOQA/EK June 13, 1933. L. w. LARSEN PROCESS OF TREATING GRAINS 1930 4 Sheets-Sheet 3 Filed June 18 Arrakxvs June 13, 1933. 1.. w.v LARSEN 1,914,341

PROCESS OF TREATING GRAINS Filed June 18, 1930 4 Sheets-Sheet 4 Z- MA k I649 'ATTOEWEK Patented June 13,

UNITE srres PAranr 'orrica LAWRENCE W. LARSEN', 0E MARINETTE, WISCONSIN, ASSIGNOR TO ANSUL CHEMICAL COMPANY, OF MARINETTE, WISCONSIN, A CORPORATION OF WISCONSIN PROCESS OF TREATING GRAINS Application filed June 18,

The invention relates to an improved process which is especially adapted for sulphuriz ing grains for the purpose of removing stain, must and mold from such grains as oats, barley and the like.

The bleaching of grain, and particularly oats and barely, by treatment with the fumes of burning sulphur is an old and established practice. In its essentials, this prior practice consists in treating a stream of grain descending through a tower with a mixture of steam and the fumes of the burning sulphur. The forms of apparatus that have been employed are varied but in all of them known to me the treatment comprises the essential steps here mentioned. In these prior treatments the bleaching action is, of course,

due to the formation on the grains of sulphurous acid resulting from the absorption by the condensed moisture of the sulphurous oxide fumes.

The prior methods of treatment referred to have several serious disadvantages. First, the grain is warmed to such an extent by the use of the steam that the bleaching treatment must ordinarily be followed by some.

cooling treatment such as passing it through an aspirator or through an elevator one ormore times, to prevent undue heating of the grain subsequently. Second, it has not been possible to control the amount of moisture introduced into the grain closely enough to prevent excess moisture and the resultant necessity of partially drying the grainafter treatment to prevent overheating during sub sequent storage. Third, the volume of gases which must be handled in the prior treatments is extremely large because the sulphur fumes are largely diluted with air so that it is necessary to use a treating tower of large size in proportion to the quantity of grain treated. Fourth, the cost of installing apparatus such as the prior sulphurizing treat ment requires is relatively h1gh, a typical apparatus comprising a large concrete and steel tower, an oven type sulphur burner and a steam boiler plant. Fifth, the cost of upkeep on the prior type of apparatus, such as is referred to, 1s veryhigh by reason of the 1930. Serial no.) 462,058.

mg treatment that is more efficient and efiective than the prior methods (2) the provision of a sulphurizing treatment which is subject to very nice c'ontrol of the bleaching or treatmg agent; (3) the avoidance of overheating and overmoist-ening of the grain with the resultant avoidance of the labor and expense of rehandling of the grain to cool and dry it; (4) the provision of a method by which grain an be effectively treated without the handling ot a large volume of air or other gases 8 and at a very rapid rate; (5) the provision. of a sulphurizing process which is susceptible of being carried out by apparatus that is exceedingly simple, with a low first cost and very moderate upkeep costs; (6) the provision of a sulphurizing treatment which is susceptible of being carried out by apparatus that is both simple'and applicable to a great variety of operating conditions such as are encountered'in grain elevators; (7) the provision of a grain sulphurizing treatment adapted to be conveniently and effectively carried Out in grain elevator and storage buildings without incurring any added fire hazard; and

other objects, more or less incidental or ancilso lary to the foregoing, which will be apparent from the following description.

My improved process, in its preferred form, consists essentially in diffusing the grain to be treated, as by showering or streaming it into a bin or chamber, spraying it while in the diflused state with water at ordinary temperature and in predetermined amount to suitably moisten it, and either simultaneously or immediately after spraying it with water also spraying it with liquid sulphur dioxide in predetermined amounts.

When the grain is sprayed simultaneously with water and S0 the two liquids combine,

forming a cloud-like body of sulphurous acid through which the grain passes so that the individual kernels are effectively coated with the acid. When the SO spray follows the water spray the sulphur dioxide dissolves in the film of moisture on the individual grains or kernels, forming thereon a coating of sulphurous acid. In either case, by proper control of the moisture and the liquid S0 the amount and concentration of the sulphurous acid can be nicely controlled to effect the desired treatment.

The desired control of the sprayed liquids is readily attained by the use of suitable calibrated spraying nozzles in conjunction with suitable control valves and pressure gauges, the control valves being adjusted to maintain liquid pressures at the nozzles suitably proportioned to the rate of floiv of the grain to apply to the latter the predetermined amount of treating solution.

\Vith the nice control of the treating liquid which is thus made possible, overwetting of the grain is avoided. Also since water at the ordinary temperatures of the room or surrounding atmosphere is used, rather than the steam or hot vapors of water which characterize former processes, there is no substantial heating of the grain during the treatment and the result is that subsequent handling to cool or dry the grain is unnecessary. Indeed it is entirely feasible with my process to treat the grain as it is discharged or showered into the storage bin and be assured that very effective bleaching is carried out without further treatment. While the treating solution which is applied to the grain in accordance with my process is less in amount than the liquid that has been ap plied in prior processes (with the resultant avoidance of overwetting the grain), the

treating solution, for reasons which I will.

later explain, is more concentrated and thus more effective in its bleaching action. Grain which is treated by my process as it is showered into a storage bin is found at the end of twenty-four hours to be very thoroughly and effectively bleached. Furthermore,

by using the liquid reagent $0. in the manner stated above the reagent is very effectively applied to the grain and loss of re.-

agent is minimized.

- In order that my improved process and the numerous advantages attaching to it may be clearly understood and appreciated, I shall now describe the carrying out of the process in detail with reference to apparatus which may be suitably employed in connection with typical grain elevator appliances.

In the accompanying drawings illustrating the apparatus, Fig. 1 is a more or less schematic vertical section of a grain elevator of typical construction and arrangement.

Fig. 2 is a fragmentary section on the line 22 through the conveyor gallery of the elevator.

Fig. 2 is a fragmentary view showipg a construction detail.

Fig. 3 is an enlarged vertical sectional view of one forni of my improved treating apparatus arranged at the grain inlet opening at the top of one of the storage bins.

. Fig. 4 is a horizontal section on the line- Fig. 5 is a vertical section on the line 55,

Fig. 4, i. e. at right angles to the section of Fig. 9 is a section on the broken line 9-9 of Fig. 8.

Fig. 10 is a plan view of the treating apparatus shown in Figs. 8 and 9.

Referring in detail to the apparatus illustrated and first to Figs. 1 to 5, inclusive, Fig. 1 illustrates a typical form of grain elevator comprising a main or working house 1, a series of cylindrical storage bins 2 which are arranged in two rows (Fig. 2), and which are topped'by a conveyor gallery 3.

The working house 1 is provided with one or more elevator legs 4. The elevator 4 has its boot 4 arranged below the normal ground level at the bottom of the working house and its discharge head 4" at the top of the house. At the ground level the working house is pro vided with a grain receiving pit 5 over which freight cars may run and dlscharge their contents, as indicated in Fig. 1. The pit 5 has its discharge spout arranged to deliver into the boot 4- of the elevator leg. The working house also contains one or more shi ping and treating bins 6. Each such bin is tted at its lower end with a discharge spout 6' arranged to deliver grain into freight cars, as indicated, and with a discharge spout 6 which is arranged to deliver into the boot 4 of the elevator le The head of the elevator leg has its disc arge spout 4 arranged to deliver into a distributing hopper 7 at the top of the house and this hopper has bottom discharge I spouts one of which 7 is adapted to disc arge into the bin 6 and another of which 7 is arran ed to discharge into .a gamer hopper 8 whie in turn is arranged to discharge into a sealehopper 9.

The scale hopper 9 is arran to discharge in turn upon t e main distri uting belt conveyor 10 which extends from the working house through the gallery 3 which tops the storage bins 2. The conveyor 10 is provided with a tripper or a throw-ofi carriage which is designated as an entirety by 11 and which runs upon track rails 12 extending longitudinally of the gall As shown in Fig. 2 the tripper is pnovi ed with two uts 13, 13 which extend from opposite sides of the tripper to deliver discharged from the conve or into e top or receivingopeningsofei errow ofbins.

lhe storage bins 2 have hopper bottoms 2 and discharge spouts 2 which are arranged to discharge grain upon a conveyor 14 which extends beneath the storage bins andhas its delivery end arranged within the working house 1 to discharge into a chute which is arranged to deliver grain into the elevator boot 4 All of the foregoing structural features and apparatus are typical of present day grain elevator practice and will be readily understood by those familiar with such structures without further description and explanation.

Referring now more particularly to the apparatus and equipment by which the elevator plant illustrated is adapted for the carrying out of my improved process, Figs. 3, 4 and 5 illustrate preferred apparatus for spraying the grain,.as it is discharged from the conveyor. tripper into the storage bins, with water and with liquid sulphur dioxide.

The top wall 2 of each storage bin, (thesetop walls of the bins alsoconstituting the floor of the conveyor gallery 3), is formed with a grain receiving opening 2 of rectangular outline. For. the purpose of treating the grain as it leaves the tripper spout 13 and is showered through the receiving opening 2 into the bin, 1 provide a water spraying equipment comprising a rectangular spraying head 16, formed of suitable p1pe sections and fittings, which is connected at one corner with a supply pipe 17 and is fitted with a series of spray nozzles 18 which extend downward and inward at an inclination of 45, there being six of these water spraying nozzles in the construction illustrated. The supply pipe 17 is fitted with a manual control valve 19 by which the pressure in the rectangular spray head 16 can be varied at will and the supply pipe 17 is also fitted-on the discharge side of the control valve 19 with a pressure gauge 20 by which the operator can beguided in adjusting the valve 19 to secure the desired pressure on the spray nozzles.

Similarly the spraying apparatus is pro-- vided with a straight spray head 21 for liquid sulphur dioxide, said spray head consisting of pipe sections and fittings, and this spray head is fitted with a pair ofspray nozzles 22, 22 which extend directly downward. To the spray head 21 is connected a supply pipe 23 which is fitted with a manual control valve 24 and a pressure gauge 25.

The spray nozzles 22 should be made of material that will not be corroded by sulphurous acid fumes. Spray nozzles of the type used in the manufacture of chamber acid are suitable for this purpose and'I have found Monarch chamber sprays having a 7 In. m.

, orifice very satisfactory. I have also found tips and is not attacked by the sulphurous rest upon the floor 2 with its nozzles project-- ing into the floor opening, while the spray head 21 rests upon the spray head 16 and is disposed on the longitudinal axis of the latter. To hold the two spray heads in this assembled relation to each other, I provide a rectangular wood frame 26 which fits around the spray head 16 and is formed with notches on its under side to accommodate the supply pipe 17 and the spray head 21. To prevent the escape of sulphurous fumes from the bin into the conveyor gallery and elevator house, the tripper spout 13 is fitted with a skirt 27 of heavy, closely woven canvas and the lower edge of this skirt is secured to the rectangular frame 26.

Water is supplied to the spray apparatus the working house a motor driven pump 31 which may suitably be a small-gear pump provided with a pressure by-pass valve which automatically insures delivery of the water at the desired pressure. In installing a water supply line it is to be bornein mind that grain elevators are usually below freezing temperature in cold weather. The upright water supply line 30 can readily be drained when the grain treating apparatus is not in use, but as there is more difficulty in draining a horizontal. line running through the conveyor gallery I prefer to use the hose line 28 to carry the water from the upright water pipe 30 to the spray nozzles.

Liquid S0 is delivered to the supply pipe.

23 of the spray head 21 by means of a section of flexible copper tubing 32 which is coupled at one end to the supply pipe 23 of the spray head 21 and at its other end has a cut-off valve fitting 32 which is adapted to be removably coupled to a liquid SO supply pipe or tube 33 at any one of the series of valved fittings 34 with which the tube 33 is provided through the working house to a su [ply tank- 36. This supply tank is fitted wit a motor.

driven air pump 37 which forces the -liquid SO, from the tank through the tubes 35, 33 and 32 to the spray head.

To provide for the free escape of excess sulphurous fumes from the bins, each bin 5 which is to be used in the treating of the grain is fitted with a vent pipe 38 (Fig. 2) which extends through the side wall of the gallery house and has its downwardly projecting outer end Open 'to the atmosphere. It will be understood that during the treating of the grain the bin gradually fills with grain thereby displacing air which must be vented. This air becomes mixed with the sulphurous fumes and it is this mixture of air and fumes which .is carried to the outer atmosphere through the vent 38.

In order that the carrying out of the process may be clearly understood, I will now describe the bleaching of grain, oats for example, with the equipment which has been described. The grain to be bleached, which may be drawn either from the receiving pit 5 of the elevator or from some one of the storage bins 2 or even from one of the shipping bins 6 in the main working house, is in any case delivered into the boot 4 of the elevator 4 by which it is lifted to, the top of the house and delivered into the hopper 7, and in case the treated grain is to be delivered into one of the storage bins 2, the said grain is discharged from the hopper 7 through the garner 8 and into the scale hopper 9 from which it may be discharged at a suitable predetermined r'ate upon the belt conveyor 10. The rate of discharge of grain upon the belt conveyor can readily be controlled by adjusting the discharge slide of the scale hopr until the discharge of grain is at the esired rate as shown by the scales. The tripper 11 having been positioned to discharge into the particular bin 2 in which the bleached grain is to be stored, the spray apparatus is connected up with the tripper discharge spout 13 with the spray heads properly positioned in relation to the inlet opemng of the bin and the water and sulphur dioxide lines are connected in the manner previously indicated. When the flow of grain starts the water and liquid SO valves are uickly adjusted to positions which give the esired ressure upon the spray nozzles as indicated y the respective pressure gauges 20 and 25. The pressures at which the water and liquid SO, supply valves are set will depend upon the rate of flow of the grain upon the concentration of the liquid treating agent which it is desired to apply to the grain. Ap aratus such as I have illustrated .and descri is capable of, treating from 5000 to 7500 bushels of grain .per hour. For the treatment of 7500 bushels of oats per hour,

with spray nozzles of the character previously specified, the water should be sprayed at -a pressure of approximately 17 pounds per square inch and the liquid SO, should be sprayed at a pressure of approximately 21 pounds per square inch. This will app y to the grain approximately 1% by weight of water and 0.12 of a pound of sulphur dioxide per bushel. These amounts of water and sulphur dioxide per bushel of grain are suitable for an ordinary or typical case of grain requiring bleaching. It. will, of course, be understood that the amount of water used will vary with the degree of dryness of the grain to be treated and that the amount of sulphur dioxide will vary with the condition of the grain in other respects so as to give a sulphurous acid of suitable concentration to do the work. According to my experience in the use of the process, the amount of water which should be sprayed upon the grain will fall within the range of 1% to 3% of the weight of the grain and the amount of liquid sulphur dioxide employed will fall within the range of 0.05 .pounds to 0.50 pounds per bushel of grain, although in'the great ma- .jority of cases the sulphur dioxide required will probably be within the range of 0.1 to 0.3 pounds per bushel of grain.

Obviously by making a series of tests the spray nozzles employed can easily be calibrated so that the weight of water and liquid S0 respectively delivered at diflerent pres- .sures may be known and any desired amount of water and liquid SO applied per bushel of grain. As the sulphur dioxide, as well as the water, is meteredin the liquid state the control of the treating agent as well as of the water is very accurate and dependable and any desired concentration of sulphurous acid may be applied to the grain.

As the grain delivered from the tripper spout is struck by the sprays of water and liquid SO the individual grains or kernels are given a resulting coating of sulphurous acid and, thus coated, the grain falls into the bin. As the grain lies in quiescent state in the bin the bleaching action proceeds and is ordinarily complete within twenty-four hours. The close control of the moisture which is supplied to the grain makes it possible to avoid adding moisture in excess of what may properly be added without the danger of causing overheating of the grain and consequently it is not necessary to subect the grain after treatment to any further handling to effect drying. Thus grain can be very rapidly treated as it is delivered into the storage bins with practically no more labor and handling than would be required in effecting the storage without the treatment.

Obviously the apparatus employed to ap ply the treating reagent in accordance with my improved process, make take a great variety of forms. While for most purposes I prefer the form of spraying apparatus illustrated in 3, 4 and 5, because of its low cost, simplicity, portability, ease of handling and general effectiveness. I have. illustrated in Figs. 6 to 10 some other forms of spraying apparatus which I will now briefly describe.

The apparatus shown in Fig. 6 is also illustrated as applied to the shipping bin 6 in the working house of the elevator shownin Fig. 1. In this construction the top wall 6 of-the bin 6 has its grain inlet opening supplied with a floor plate 39 in the threaded opening of which is adjustably mounted the grain hopper 40 which is arranged to receive the grain from the spout 7 a of the hopper 7 (Fig. 1). Within the bin and directly below the discharge of the hopper 40 is arranged a corrugated dispersing cone 41 from which the grain flows in a diffused state as it is discharged into the bin. A water spray head 42 is supplied with a series of depending spray nozzles 43 which are arranged to spray water upon the difiused grain as it flows over and is discharged from the cone 41. The spray head 42 is supplied by a water line 44 which extends to and is connected with the main water supply pipe 30, the pipe 44 being fitted with a control valve 45 and a pressure gauge 46. Below the dispersing cone 41 is arranged a spray head 47 which carries a series of S0 spray nozzles 48, 48 which are arranged horizontally to project a spray of liquid S0 upon the grain as it is discharged from the cone 41. The spray head 47 is supplied with liquid S0 by a tube 49 which connects with the main supply tube 35. The tube 49 is fitted with'a con trol valve 50 and a pressure gauge 51. The discharge slide of the hopper 7 can be calibrated to regulate the rate of flow of grain through the spout '7 and in addition the flow of grain over the dispersing cone 41 can be controlled by turning the hopper 40 to adjust it upwardand downward in relation to the cone 41.

The bin 6 is preferably provided with a vent 52 for discharge of excess air and fumes from the bin in the manner described in connection with the bins 2.

lit will be seen that grain can be treated in connection with the bin 6 and either immediately discharged into freight cars after the treatment is completed or the bin can, after the treatment is complete, be discharged through the spout 6 into the boot of the elevator 4 and thence lifted and delivered by the conveyor 10 into any one of the storage bins 2.

In Fig. 7 I have shown a second modified form of spraying apparatus. Here the bin 53 has its top wall 53 provided with a floor plate 54 in which a hopper 55 is adjustablyv mounted as in the case of the construction I shown in Fig. 6 and there is provided a water spray head 56 with depending spray nozzles 56 of the same character as the water spray head shown in Fig. 6. However, in this last construction there is provided in lieu of the dispersing cone of Fig. 6 a rotatable disk 57 which is arranged horizontally below the discharge end of the hopper 55.

The disk is supported by a bearing 58 in which is mounted a drive shaft 59 carrying a bevel gear 60 which in turn is driven by a bevel gear 61 on a horizontal shaft 62 that extends through the side wall of the bin, with bearing supports as shown, and is provided with a driving pulley 63 or any other suitable means for applying power to said shaft. The rotation of the disk 57 causes the grain delivered upon the disk from the hopper 55 to be showered from the edge of the disk into the bin. The water spray nozzles 56 deliver a spray of water upon the grain as it is showered from the disk and simultaneously a series of The water and liquid S0 supply lines are fitted with control valves and pressure gauges of the same character as previously described.

In Figs. 8, 9 and 10 I have shown still another modified form of spraying apparatus. Here the bin 66 has its top wall 66 provided with the usual grain inlet opening above which is mounted a grain hopper 67, the bottom of which is formed with two slot-like openings 67, 67 through which streams of grain may be discharged into the bin. On the under side of the hopper is mounted a bifurcated water spray head 68 fitted with nozzles 68* adapted to project sprays of water against the streams of grain issuing from the hopper. And similarly a spray head 69 having a series of spray nozzles 69 is adapted to project sprays of liquid S02 upon the streams of grain.

As in the former constructions, the water and liquid SO 'sprayS are supplied through pipes fitted with control valves and pressure gauges so that the water and the bleaching agent can be nicely controlled.

From a consideration of the various forms of construction illustrated, it is obvious that the spraying apparatus may take a great variety of forms, the only essential thing being to provide suitable spray nozzles properly mounted to spray the grain while in a diffuse state with water and the liquid treating agent, and to provide means by which the rate of flow of the two liquids can be readily controlled.

By a comparison of the several forms of spray apparatus, the marked simplicity of the form shown in Figs. 3, 4 and 5 will be appreciated. It will be observed that while the water and liquid S0 spray heads are effectively held in working relation by the simple wooden frame26, it is possible to .quickly separate the two spray heads by to bin by simply disconnecting the S tube 32 from the supply line 33.

On the other hand some elevators or grain storage houses do not have covered bins fed 5 by conveyor belt and tripper. In such instances it may be advisable to devote a single bin to the sulphurizing treatment and a fixed installation of the spraying apparatus is entirely suitable in these cases.

My improved process of treating grain has numerous advantages which will be readily appreciated by those familiar with the prior methods of treatment. By avoiding the use of steam and the consequent heating of the in I avoid the necessity of a subsequent handling of the grain to cool it and prevent its overheating in storage. In addition, by not heating the grain I"am enabled to apply to the grain a more concentrated sulphurous acid since the solubility of sulphur dioxide and water varies with the temperature, being much higher at moderate temperatures than at the high temperatures caused by the use of steam in the prior methods of sulphurizing. The more concentrated sulphurous acid attained by my process makes possible a more ra id and effective treatment of the grain.

e advantage of my process incident to the avoidance of introducing an excess of moisture into the grain is quite obvious as it avoids the labor and expense of handling the grain to effect drying following the sulphurizing treatment. Furthermore, the close control of the moisture is advantageous because of the laws and regulations relating to rmissible amounts of moisture in grain that is marketed.

By applying the treating agent directly to thtrgagrain in liquid form and avoiding the inaction of air or other diluent gases into the treating bin or chamber I, at the same time, secure marked efiiciency and effective ness of bleaching and avoid the serious problem of handling large volumes of air or gases which has characterized prior sulphurizing treatments. I am. thus enabled, by the use of very simple and inexpensive apparatus, to treat in efiectively at a relatively rapid rate. us the simple treating apparatus which I have illustrated in Figs. 1 to 5 is capable of treating 7500 bushels of grain per .hour, whereas by prior methods known to me a treating apparatus which would cost several times as much as my apparatus has a treating capacity very much lower than 7500 bushels r hour.

As noted in the first part of this specification, 111 method of ap lying the reagent in liquid orm insures efi ective application of the-reagent to the grain with a 10$ of the ru'fint. This result is due in. part to the t the reagent is applied to the grain while the latter isin a diffuse state and I m part to the fact that the cloud or mist of sulphur-cue acid formed by bringing the liquid S0 and water together settles upon the grain in the bin as it accumulates therein and only a relatively small part of the mist is carried out through'the ventilating flue and lost.

Furthermore, by applyingthe pure liquid S0 directly to the-moistened grain I delay the formation of the sulphurous acid until the actual point of application to the grain and thus greatly lessen corrosive efi'ects upon metal parts of the apparatus and correspondingly reduce upkeep charges' As my grain treating process does not necessitate the use of a furnace or other heating equipment, it can be carried out in any building without any added fire hazard.

Obviously; as has been pointed out, the process lends itself to the use of various forms of apparatus and can be carried out with apparatus of marked simplicity and low cost an in consequence the process can be installed for effective use at very moderate cost for operation under widely varying conditions.

I make no claim in the present application to the novel features of the apparatus which has been shown and described as said features constitute the subject of my copending application Serial No. 482,777 filed September 18,1930. V

While I have described a specific procedure in carrying out my process, it is to be understood that this has been done for clarity of disclosure and explanation and that the process is not limited to the specific procedure described except as indicated in the appended claims.

- What I claim is: x

1. The process oftreating grain which comprises diffusing the grain,and spraying the grain while in the diffused state with water in predetermined amount per bushel of grain and with liquid sulphur dioxide in predetermined amount per bushel of grain to form sulphurous acid of predetermined concentration upon the surface of the grain.

2. The process of treating grain which comprlses diffusing the grain, spraying the grain while in the diffused state with water in predetermined amount per bushel of grain, and simultaneously spraying the aim with liquid sulphur dioxide in pr etermined amount per bushel of grain to form sulphurous acid of predetermined concentration upon the surface of the grain.

3. The process of treating grain which comprises difiusing the grain, spraying the gram while in the difiused state with water in predetermined amount per bushel of in, an thereafter spraying'the grain while in the difiused state with hquid sulphur dioxide in predetermined amount per bushel of grain, to form sulphurous acid of predetermined :oncentration upon the surface of the grain. w

4. The process of treating grain which comprises diffusing the grain, and spraying the grain while in the diffused state with water in predetermined amount 7 ranging from 1% to 3% of the Weight of. the grain and with liquid sulphur dioxide in predetermined amount ranging from 0.05 pound to 0.50 pound per bushel of grain, thereby forming sulphurous acid of predetermined c0n-' ceutration upon the surface of the grain.

In testimony whereof, I hereunto aflix my signature.

- LAWRENCE W. LARSEN. 

